A Russian banker accused in the United States of participating in a spy ring has pleaded guilty to conspiracy.

Yevgeny Buryakov pleaded guilty on March 11 to conspiring with others to act as an agent of a foreign government without registering with the U.S. government.

The guilty plea was announced by the U.S. assistant attorney general for national security, John P. Carlin.

Prosecutors said that from 2012 through January 2015 he teamed up with diplomats to gather sensitive economic intelligence on potential U.S. sanctions against Russian banks and on U.S. efforts to develop alternative energy resources.

Buryakov had previously pleaded not guilty to conspiracy and other charges alleging he purposely failed to register as a foreign agent.

He allegedly was seeking to conceal his true role as a covert operative embedded at a Manhattan branch of Vneshekonombank (VEB).

He remains behind bars until sentencing, which is scheduled for May 25.